The present invention relates to a method and an exchange for cascade accounting of connection-oriented communication sessions which are maintained between a first and a second subscriber station of a telecommunication system operating with connection-oriented services. The telecommunication system comprises a first network serving a plurality of said first subscriber stations, at least one transit network and a second network serving a plurality of said second subscriber stations. Each network comprises at least one exchange having a plurality of incoming communication resources and outgoing communication resources for respectively handling forward signalling messages and backward signalling messages sent in the direction from the first subscriber station to the second subscriber station and in the direction from the second subscriber station to the first subscriber station.
The class of telecommunication systems considered by the present invention relates to connection-oriented telecommunication systems in which a respective connection-oriented communication session between a first and second subscriber station is typically conducted in two stages. In a first stage communication request and communication confirmation messages are exchanged between the first and second subscriber station to negotiate and set in each exchange of the first network, the transit network and the second network communication data which clearly define the path (a logical pipe) between all incoming and outgoing communication resources of the respective exchanges. In the second phase the actual transfer of data messages (and other signalling messages) is carried out only along this predefined logical path. Only the communication request message contains routing data and an identification of the called subscriber station. Optionally, the connection confirmation might as well can contain such data types.
Since a connection (path) is predefined by the exchange of the request and confirmation messages, such communication sessions are called xe2x80x9cconnection-orientedxe2x80x9d. By contrast, in connectionless communication sessions each signalling message of the communication session contains routing data and identifications of the called subscriber station such that each message may be routed through a different path such that each signalling message may use different sets of incoming and outgoing communication resources. Since for each signalling message the transfer path may change, such communication sessions are called xe2x80x9cconnectionlessxe2x80x9d i.e. without a preset connection.
In both types of telecommunication systems the transit network (and also the first and the second network) must carry out accounting procedures of the signalling traffic received from the first and second network in order to appropriately charge both networks for the routing of the signalling messages. The counting is typically done by counting the number of routed signalling messages and/the number of octets (the amount of data) transferred by each message. Since in a connection-less telecommunication system each signalling message contains the routing data as well as the called party identification the transit network has no problems to relate each received and transmitted signalling message to a particular communication session. Thus, an accurate accounting relating the respective signalling traffic to the correct communication session can be performed.
However, in connection-oriented telecommunication systems used nowadays, only the connection request and optionally the request confirmation message contains the routing data and called party identification (for setting the logical path) and the subsequent messages lack this information such that only the first messages of the communication session can be used for accounting purposes. Thus, the accounting is not very accurate. The present invention in particular addresses the problem how an accurate accounting can be provided for the signalling traffic in a connection-oriented telecommunication system.
Although hereinafter the background of the invention will be described in terms of the Connection-Oriented service offered by the Signalling Connection Control Part (hereinafter denoted with SCCP) of the Signalling System Number 7 (hereinafter denoted SS7) similar considerations hold for any other connection-oriented telecommunication system.
In the telecommunication networks which make use of the xe2x80x9cSignalling System Number 7xe2x80x9d different network operators are given the means to charge each other for the use of own network resources and also to verify by themselves that they are correctly charged by other network operators. However, as generally mentioned above for general connection-oriented telecommunication systems, also the SCCP SS7 telecommunication system suffers from the fact that the accounting is not very accurate. This will be explained below with more details regarding the background of the invention.
Currently existing telecommunication networks, both wireline and wireless related networks, still make use of the xe2x80x9cCommon Channel Signalling System Number 7 (hereinafter SS7) protocol stack to implement layers lower than the application layer according to the OSI model.
Said SS7 protocol stack consists of different parts, standardised by ITU-T and ANSI Recommendations. For the purpose of the present invention, just one of them, the Signalling Connection Control Part (hereinafter SCCP), is affected.
Under said SCCP there must be an appropriate protocol stack to build up the Physical, Link and Network layers. Traditionally, the Message Transport Part described by ITU-T and part of SS7, provided these lower three layers above. Nowadays, and justified by the wide growth of Internet, other protocol means can replace the older MTP for this purpose such as the Transmission Control Protocol (hereinafter TCP), or User Datagram Protocol (hereinafter UDP), or the recently suggested Simple Control Transmission Protocol (hereinafter SCTP) over the Internet Protocol (hereinafter IP).
As already explained above for a general connection-oriented system, from a signalling transmission point of view, two different sorts of services are also provided by SCCP, namely Connectionless and Connection-Oriented services.
As above mentioned, the main difference to outline between both services, for the purpose of the present invention, is that all the individual signalling exchanged within the connectionless service contains routing data and identifiers of the Called Party. However, this is not the case within the Connection-Oriented service wherein just the initial Connection Request message contains routing data and identifiers of the Called Party. For the sake of clarity it should be noticed that the Connection Confirm message could also contain routing data and identifiers of the Called Party, however, since these parameters are optional in said Connection Confirm message, other standard mechanisms apply as routing such messages.
Well-known functionalities of the SCCP Connectionless service are the Mobile Application Part used by GSM and the Intelligent Network Application Part, whereas well-known functionalities of the Connection-Oriented service are the Base Station System Application Part, also used by GSM, and the Radio Access Network Application Part used by UMTS (Universal Mobile Telecommunication System).
An important concept for the purpose of the present invention, is the meaning of Accounting and, more specifically, the SCCP Accounting. Accounting basically relates to the necessity that the different SS7 network operators have to charge each other for the use of own network resources as well as have to verify themselves that they are correctly charged by other operators. Both features together are referred to as Accounting. Given that these features, charging and verification, are taken into consideration when transferring signalling between different network operators, the invocation of such features is absolutely depending on the routing analysis result. As a direct consequence of this dependency between routing results and charging or verification invocation, both routing and accounting require similar sets of parameters, and both take place at the same layers in the SS7 protocol stack, namely SCCP and MTP. For the purpose of the present invention, further and deeper explanations are only provided for SCCP Accounting.
SCCP Accounting between operators uses the concept of Cascade Accounting as illustrated in FIG. 1. The assumption for the example in FIG. 1 is that Network Operator A of the first network A is the originating end user and Network Operator D of the second network D is the destination end user, whereas Network Operator B and Network Operator C are transit networks. Under this assumption, the Network Operator B will charge the Network Operator A for transmitting his signalling towards the Network Operator C. Based on the same principle, the Network Operator C will charge the Network Operator B for transmitting his signalling towards the Network Operator D.
The principle behind this method is that the operator of a signalling point N10 originating a message pays the operator owning the next signalling point N20 for the signalling path to be followed for delivering such a message. The latter signalling point N20 pays the operator that owns the next signalling point N30 for the signalling path, and so on. In this accounting method, intermediate signalling points owned by the same operator as the previous signalling point are not an object of accounting. The method rather applies to those signalling points for which the next signalling point encountered in a message path is owned by a different operator.
In the Cascade Accounting method, two main accounting concepts are used. On the one hand, the Remuneration Accounting F20, F30 is the measurement of signalling traffic received from an operator S10, S20. This measurement is used to charge other operators A, B for their usage of the own signalling point related resources N20, N30. On the other hand, the Verification Accounting F15, F25 is the measurement of signalling traffic sent towards another operator S10, S20. This measurement is used to verify that the own signalling point N10, N20 is correctly charged from other operators (B, C) for the usage of their resources (N20, N30).
In order to apply the principles above, and more specifically, for SCCP Accounting, the operator has to establish appropriate accounting criteria. Under these accounting criteria, measurements can be made of the SCCP signalling traffic. Moreover, these accounting criteria are very closely related to those SCCP parameters needed by the routing analysis function.
In this respect, examples of such SCCP parameters are the Global Title (hereinafter GT), the applicable Signalling Point Code (hereinafter SPC) and, optionally, the Subsystem Number (hereinafter SSN). Still another SCCP parameter, which is not directly used by the routing analysis function though significant for accounting, is the Protocol Class (hereinafter PCLASS) parameter used in particular to differentiate between SCCP Connectionless and SCCP Connection-Oriented services.
The SPC is a number that designates a Signalling Point of a certain network. Said SPC is commonly referred to either as Originating signalling Point Code (hereinafter OPC), or as Destination signalling Point Code (hereinafter DPC) depending on whether the accounted SCCP message comes from the former or goes to the latter. The SSN is a number that designates an application or, in other words, an SCCP user. A GT is an address, such as dialed digits, that unambiguously identifies the entity or application making use of the SCCP services. The GT must be translated during the routing process to get a destination in the SCCP network for the processed message. This destination is normally obtained in terms of a DPC accompanied or not by an SSN.
More specifically, for SCCP Connection-Oriented service, the Global Title is only used for routing during the connection establishment phase when a Connection Request message is processed. Even though the Connection Confirm message could occasionally contain a GT, other mechanisms can apply as well so that such a Connection-Oriented message can not be considered instance of GT based routing. As generally explained above, once the connection is established the subsequent messages do not include GT and the routing is based on the corresponding Connection Sections identifiers.
A Connection Section (hereinafter CS) represents the logical path between two signalling points within a logical signalling association between two connection-oriented SCCP users. This signalling association may consist of one or more Connection Sections. These Connection Sections are dynamically distributed and are only alive during the connection session lifetime.
FIG. 2 illustrates this concept as well as its further applicability for routing of Connection-Oriented signalling other than Connection Request messages. The end user node (Exchange A) originating a Connection Request message CR assigns an outgoing Connection Section outCS-a that is included as sending said CR message. When such a CR message is received in the first transit node (Exchange B), and when a next transit node (exchange C) is determined from the routing analysis, an incoming inCS-b and an outgoing outCS-b Connection Section are assigned and internally linked. Besides, the outgoing Connection Section outCS-b is determined as sending the CR message. When such a CR message is received in the next transit node (Exchange C) a similar process as for the previous node takes place, and said CR message is sent to the destination end user (Exchange D) with the latest outgoing Connection Section outCS-c. When said CR message is received at the destination end user (Exchange D), an incoming Connection Section inCS-d is assigned, such a message is processed and delivered to the application, and a Connection Confirm message CC is sent backwards. Said CC message includes the recently assigned incoming Connection Section (inCS-d) as well as the outgoing Connection Section outCS-c received from the previous node.
The node receiving said CC message (Exchange C) gets from an internal association the incoming Connection Section incCS-c linked to the received one outCS-c wherein said incoming Connection Section incCS-c contains data such as the outgoing Connection Section outCS-b from the originating side. Then, such a CC message is sent back to the previous node (Exchange B) with the own Connection Section identifier, now incCS-c, and the receiver one outCS-b. When such a CC message is received in next backward node (Exchange B) a similar process takes place, and said CC message is sent backwards with the own Connection Section inCS-b and the receiver Connection Section outCS-a.
From now on, all the subsequent messages from both end users, other than CR and CC indeed, for example forward and backward data messages DT1, DT2, are sent throughout the path linked by means of Connection Sections identifiers.
Under these assumptions, the accounting criteria (an accounting parameter set) are built up by the operator as a unique combination of the SCCP parameters for example, specifically, the OPC, DPC, and Called Party GT (and possibly also SSN, PCLASS). The SCCP messages, both received at a certain SCCP node and those to be sent towards another SCCP node, are analysed versus these accounting criteria in the accounting parameter set.
When the message parameters (or generally a communication or call parameter set) of a certain SCCP message under analysis match an accounting criterion parameter set defined by the operator, the message is registered either in the corresponding Remuneration Counter e.g. F21 if the message is incoming, or in the Verification Counter, e.g. F26 if the message is outgoing.
FIG. 1 shows how outgoing signalling traffic S10, sent from the SCCP layer in a Signalling Point N10, triggers the invocation of Verification Accounting F15 and registration of Verification Counters F16. FIG. 1 also shows how incoming signalling traffic S10, received at the SCCP layer in a Signalling Point N20, triggers the invocation of Remuneration Accounting F20 and registration of Remuneration Counters F21. Both Remuneration and Verification counters F21 and F16 respectively) are aimed to match each other. A similar principle applies to the signalling S20 sent from the Signalling Point N20 in network B and received in the Signalling Point N30 in network C, and the way in which the corresponding Verification Function F25, Verification Counter F26, Remuneration Function F30 and Remuneration Counter F31 are involved.
State of Art (SCCP SS7 Accounting)
In accordance with the ITU-T Specification Q.752, the SCCP Accounting is only applicable when a Global Title Translation takes place, for example at relay nodes or gateways between SS7 networks.
As mentioned above already for a general connection-oriented system, this means that in case of Connection-Oriented signalling traffic only the Connection Request (CR) message can be accounted since said message is the only Connection-Oriented protocol related message routed on Global Title.
The rest of Connection-Oriented protocol related messages needed for a communication session are not routed on Global Title and, consequently, are excluded from the traffic registration procedures for accounting purpose.
More specifically, once the connection has been set up with a Connection Confirm (hereinafter CC) message and during the connection lifetime, the main disadvantage regarding an accurate accounting is that all the information exchanged by means of Data Form 1 (hereinafter DT1) or Data Form 2 (hereinafter DT2) messages is never registered for Accounting purposes. Furthermore, also those messages intended to release the connection, such as the Released message (hereinafter RLSD) and the Release Complete message (hereinafter RLC) are never included in the Accounting procedure.
FIG. 3a schematically shows a flow diagram of a connection set up within a Connection-Oriented service wherein just the initial CR message is registered for Accounting purposes. All the confirmation message CC and all the information exchanged by the end-users with DT1 messages as well as the release messages are ignored for Accounting purposes.
Still another explanatory flow diagram in FIG. 3b presents an example of the signalling sequence followed during call establishment and release in a Universal Mobile Telecommunication System (hereinafter UMTS) network and, in particular, the SCCP Connection-Oriented signalling exchanged between the UMTS Mobile Switching Centre (hereinafter UMSC) and the Radio Network Controller (hereinafter RNC). A Transit network Node is included between the UMSC and the RNC to justify the needs for accounting in said Transit network Node.
FIG. 3b shows a certain amount of SCCP Connection-Oriented messages, namely SCCP CR messages, SCCP CC, SCCP DT1, SCCP RLSD and SCCP RLC. Within this general procedure just the initial CR messages (1 out of 17 messages) are registered for Accounting purposes in the Transit network Node.
Bearing in mind that an accurate Accounting is necessary for operators to be able to correctly charge each other for the usage of their respective network resources, the current state of art for Accounting of Connection-Oriented service only allows the charging of the initial CR message. Consequently, the operators will be only charged depending on the number of connections requested to be set up, (i.e. on the basis of the Connection-Request message CR), rather than on the actual amount of information transmitted and on how long the connections are established.
Therefore, just mere estimations of the actual traffic can be made on the basis of the number of CR messages, rather than an accounting of the total amount of Connection-Oriented signalling exchanged between different operators. That is, operators can only make estimations based on the amount of detected CR messages registered to determine the real amount of traffic. To this end, said operators estimate the message and length averages that correspond to the specific traffic types and use cases.
As explained above, in telecommunication systems using connection-oriented services, for example connection-oriented services provided by the signalling connection control part (SCCP) of the Signalling System Number 7 (SS7), the accounting is merely based on counting the number of communication request messages (CR). Thus, in conventional connection-oriented telecommunication systems where one or more transit networks are used for routing communications, only estimations of the actual signalling traffic can be used for accounting purposes. Thus, in conventional connection-oriented telecommunication systems the accounting is very inaccurate.
Therefore, the object of the present invention is to provide an accounting method, an exchange and a telecommunication system by which more accurate measurements of the connection-oriented messages and the total amount of information transferred to and from transit networks can be obtained.
This object is solved by a method (claim 1) for cascade accounting of connection-oriented communication sessions each being maintained between a first and a second subscriber station of a telecommunication system operating with connection-oriented services and comprising the sending of forward signalling messages in the direction from said first subscriber station to said second subscriber station and backward signalling messages in the direction from said second subscriber station to said first subscriber station through said telecommunication system which includes:
a first network serving a plurality of said first subscribers stations and including at least one first exchange having a plurality of outgoing communication resources for transmitting forward signalling messages and for receiving backward signalling messages;
at least one transit network including at least one transit exchange having a plurality of incoming communication resources for receiving forward signalling messages and for transmitting backward signalling messages and a plurality of outgoing communication resources for transmitting forward signalling messages and for receiving backward signalling messages; and
a second network serving a plurality of said second subscribers stations and including at least one second exchange having a plurality of incoming communication resources for receiving forward signalling messages and for transmitting backward signalling messages, and
wherein all signalling messages belonging to the same communication session are processed along the same path through the respective exchanges by the same incoming communication resource and the same outgoing communication resource of the respective exchanges involved in the communication session,
comprising the following steps:
a) storing in each outgoing communication resource for a respective communication session
a1) a verification accounting reference parameter indicating a verification accounting means for measuring the respective signalling traffic amount of the transmitted forward signalling messages; and
a2) a remuneration accounting reference parameter indicating a remuneration accounting means for measuring the respective signalling traffic amount of received backward signalling messages;
b) storing in each incoming communication resource during said communication session
b1) a remuneration accounting reference parameter indicating a remuneration accounting means for measuring the respective signalling traffic amount of received forward signalling messages; and
b2) a verification accounting reference parameter indicating a verification accounting means for measuring the respective signalling traffic amount of the transmitted backward signalling messages of said communication session;
c1) accounting of all forward signalling messages belonging to the same communication session by measuring the signalling traffic of said forward signalling messages by the respective verification accounting means as indicated via said verification accounting reference parameter in the respective outgoing communication resource and by the respective remuneration accounting means indicated via said remuneration accounting reference parameter in the respective incoming communication resource; and
c2) accounting of all backward signalling messages belonging to the same communication session by measuring the signalling traffic of said backward signalling messages by the respective remuneration accounting means indicated via said remuneration accounting reference parameter in the respective outgoing communication resource and by the respective verification accounting means indicated via said verification accounting reference parameter in the respective incoming communication resource.
Furthermore, this object is solved by an exchange (claim 16) of a telecommunication system in which connection-oriented communication sessions are respectively maintained between a first and a second subscriber station of a telecommunication system operating with connection-oriented services by sending forward signalling messages in the direction from said first subscriber station to said second subscriber station and backward signalling messages in the direction from said second subscriber station to said first subscriber station through said telecommunication system, including:
switching means for switching said signalling messages, including:
a plurality of outgoing communication resources for transmitting forward signalling messages and for receiving backward signalling messages;
a plurality of incoming communication resources for receiving forward signalling messages and for transmitting backward signalling messages; wherein
all signalling messages belonging to the same communication session are processed in the exchange by the same incoming communication resource and/or the same outgoing communication resource; and
an accounting means for cascade accounting of said connection-oriented communication sessions, including:
a plurality of first verification accounting means for measuring the signalling traffic amount of forward signalling messages transmitted by a respective outgoing communication resource;
a plurality of first remuneration accounting means for measuring the signalling traffic amount of forward signalling messages received by a respective incoming communication resource;
a plurality of second remuneration accounting means for measuring the signalling traffic amount of backward signalling messages received by a respective outgoing communication resource; and
a plurality of second verification accounting means for measuring the signalling traffic amount of backward signalling messages transmitted by a respective incoming communication resource;
memory means in each outgoing communication resource for storing a verification accounting reference parameter indicating one of said first verification accounting means and a remuneration accounting reference parameter indicating one of said second remuneration accounting means;
memory means in each incoming communication resource for storing a remuneration accounting reference parameter indicating one of said first remuneration accounting means and a verification accounting reference parameter indicating one of said second verification accounting means;
wherein at every transmission of a forward signalling message from said outgoing communication resource, the verification accounting means indicated in said outgoing communication resource via said verification accounting reference parameter measures the signalling traffic of said transmitted forward signalling message;
wherein at every reception of a backward signalling message at said outgoing communication resource the remuneration accounting means indicated in said outgoing communication resource via said remuneration accounting reference parameter measures the signalling traffic of said received backward signalling message;
wherein at every reception of a forward signalling message at said incoming communication resource the remuneration accounting means indicated in said incoming communication resource via said remuneration accounting reference parameter measures the signalling traffic of said received forward signalling message;
wherein at every transmission of a backward signalling message at said incoming communication resource the verification accounting means indicated in said incoming communication resource via said verification accounting reference parameter measures the signalling traffic of said backward signalling message.
Furthermore, this object is solved by telecommunication system (claim 18) operating with connection-oriented services where communication sessions between a first and a second subscriber station are maintained by sending forward signalling messages in the direction from said first subscriber station to said second subscriber station and backward signalling messages in the direction from said second subscriber station to said first subscriber station through said telecommunication system, comprising:
a first network serving a plurality of said first subscribers stations and including at least one first exchange having a plurality of outgoing communication resources for transmitting forward signalling messages and for receiving backward signalling messages;
at least one transit network including at least one transit exchange having a plurality of incoming communication resources for receiving forward signalling messages and for transmitting backward signalling messages and a plurality of outgoing communication resources for transmitting forward signalling messages and for receiving backward signalling messages; and
a second network serving a plurality of said second subscribers stations and including at least one second exchange having a plurality of incoming communication resources for receiving forward signalling messages and for transmitting backward signalling messages; and
wherein each exchange is constituted as defined above.
In accordance with the invention, each outgoing communication resource contains for each communication session, a session-specific verification accounting reference parameter for measuring transmitted forward signalling message traffic and a session-specific remuneration accounting reference parameter for measuring received backward signalling message traffic. Further, in accordance with the invention, the incoming communication resource contains a session-specific remuneration accounting reference parameter for measuring the received forward signalling message traffic and a verification accounting reference parameter allowing the measurement of transmitted backward signalling message traffic. The respective accounting references point to a communication-specific accounting means which then performs the actual measurement of the traffic. Thus, whenever the same communication-session between a specific first subscriber station and a specific second subscriber station is established, always the same accounting references will be used and thus the same accounting means will account for the signalling traffic, even if a further individual communication-session between the first and second subscriber station will use a different path through the networks and thus through different incoming and outgoing communication resources. The reason is that for each subsequent call message the same accounting references will be encountered as those which were determined during the initial determination of accounting references (e.g. with the request and confirmation messages) and which were stored in the seized communication resources (incoming and outgoing).
Since each incoming communication resource and each outgoing communication resource will respectively have stored therein a verification accounting reference parameter as well as a remuneration accounting reference parameter, a more accurate accounting can be achieved because all connection-oriented messages can be controlled and registered for accounting purposes.
Thus (claim 2) whenever a forward signalling message is transmitted from an outgoing communication resource the following steps are carried out: accessing said outgoing communication resource during a communication session, reading out the verification accounting reference parameter stored therein, invoking the verification accounting means indicated by said read-out verification accounting reference parameter, and measuring the signalling traffic of said transmitted forward signalling message by said invoked verification accounting means; and whenever a forward signalling message is received by an incoming communication resource, the following steps are carried out: accessing said incoming communication resource, reading out the remuneration accounting reference parameter stored therein, invoking the remuneration accounting means indicated by said read-out remuneration accounting reference parameter, and measuring the signalling traffic of said received forward signalling message by said invoked remuneration accounting means; and whenever a backward signalling message is transmitted by said incoming communication resource, the following steps are carried out: accessing said incoming communication resource, reading out the verification accounting reference parameter stored therein, invoking said verification accounting means indicated by said read-out verification accounting reference parameter and measuring the signalling traffic of the transmitted backward signalling message by said verification accounting means; and whenever a backward signalling message is received by an outgoing communication resource, the following steps are carried out: accessing said outgoing communication resource, reading out the remuneration accounting reference parameter stored therein, invoking the remuneration accounting means indicated by said read-out remuneration accounting reference parameter, and measuring the signalling traffic of the received backward signalling message by said invoked remuneration accounting means.
Preferably, (claims 3-7), in accordance with an embodiment of the invention, each exchange can comprise an accounting memory in which a plurality of accounting parameter sets are formed. These accounting parameter sets comprise a predetermined number of parameters, namely the so-called accounting criteria. Whenever a connection-oriented signalling message is transmitted or received by a respective communication resource, a communication parameter set is derived on the basis of identifications indicating the originating and target communication resource of the signalling message, and this communication parameter set is compared with the accounting parameter sets stored in the exchange. The accounting parameter sets also comprise an indication of a verification or remuneration accounting reference parameter and the specific accounting reference parameters, in the accounting parameter set whose parameters match the derived communication parameter set, is read out and stored in the corresponding incoming or outgoing communication resource. Thus, all connection-oriented messages which match applicable accounting criteria can be controlled and registered with a negligible impact and performance.
Whilst other techniques for allocating the appropriate verification and accounting reference parameters may be used, preferably (claims 7-9), a first setting (determination) of the appropriate verification and remuneration accounting parameters in the respective incoming and outgoing communication resources is made when the first communication request message is sent from the exchange of the first network to the exchange of the second network through the one or more transmit networks and and a second setting is made when a communication confirmation backward signalling message is returned in response thereto by the second network to the first network again through the relevant transit networks. Thus, only the initial messages for setting up communications, namely the communication request message and the corresponding successful communication confirmation messages are analysed versus the defined counting criteria. Provided that the relevant communication related data (i.e. the communication parameter sets which are derived in the exchange) match an accounting criteria, the communication request and communication confirmation messages per individual communication-session can be registered for accounting purposes.
Since the accounting parameter sets stay the same even after the completion of the communication request and communication confirmation message exchange, all subsequent connection-oriented messages containing payload information can also undergo the communication parameter set determination and can find a match with the relevant accounting parameter set. Since the accounting reference parameter in the matched accounting parameter set stays the same, also the subsequent payload connection-oriented messages will be accounted for by the accounting means indicated by the accounting reference parameters. Thus, all subsequent connection-oriented messages transmitted during the communication-session (and also during a new communication-session) can be easily registered for accounting purposes.
Preferably (claim 12-15), but not exclusively, the present invention provides more accurate accounting of connection-oriented services and signalling messages which are provided by the Signalling Connection Control Part SCCP of the Signalling System Number 7 (SS7). Whilst in the SCCP SS7 telecommunication system the incoming communication resource is a SCCP SS7 Incoming Connection Section IncS, said outgoing communication resource is a SCCP SS7 outgoing connection section OutCs, said forward signalling messages comprise a SCCP SS7 communication request message, a data form 1 message, a data form 2 message, a Release Complete (RLC) message and a SCCP SS7 released (RLSD) message, said backward signalling messages comprise a SCCP SS7 communication confirm message, a Data Form 1 message, a Data Form 2 message, a release complete message (RLC) and a released message (RLSD). Corresponding communication resources and signalling messages which serve similar purposes can be found in other telecommunication systems. Therefore, the present invention should not be seen as being restricted to the SCCP SS7 telecommunication systems.
Furthermore, it should be understood that the present invention is not limited by the disclosure in the description and the claims. That is, further modifications and variations of the invention may be carried out on the basis of the teachings disclosed herein. Furthermore, the present invention may comprise embodiments which consist of steps and/or features which have been described independently in the description and/or have been claimed independently in the claims.
Further advantageous embodiments and improvements of the invention may for example be found in the dependent claims. Hereinafter, the invention will be explained with reference to what the inventors presently conceive the best mode of the invention, as illustrated with the following embodiments and with reference to the attached drawings.